It has been recognized in the field of optical displays that a coherent bundle to matrix arrangement of optical fibers produces an ideal medium for pictorial display.
By "coherent bundle to matrix arrangement" is meant that each optical fiber exposed to a source of light and an image for projection through a "projection matrix" it is connected to a display screen at a point corresponding to the respective fiber exposed to the image and light source, thereby to duplicate the image on the display screen matrix face. Generally, the fiber points in the display screen matrix face are more widely spaced from one another than are the corresponding fiber points at the light source and image-receiving matrix for the purpose of magnification of the image.
This, however, results merely in a display of a picture or indicia or a succession of same, without any other graphic variety, such as special color, brightness and other visual effects to hold viewer interest between such displays. Thus, coherent bundle displays are not widely used, particularly since motion pictures and slide projectors accomplish the same result and any desired magnification.
Although motion picture and video equipment, ranging from computer controlled light boards to television displays, will produce such special effects, their expense makes such alternative devices noncompetitive with optical fiber display devices. In addition, while a simple belt mechanism will provide low cost imaging on a coherent matrix, its readily apparent mechanical predictability is not sufficient to hold viewer interest. It is toward the solution of these problems that the present invention is directed.
The concept of a coherent bundle to matrix arrangement may best be visualized by the following:
If one were to number and mark each fiber point on a matrix display face, the fiber that leads back through the bundle to the image-receiving end must be located in the exact same location on the end of the image-receiving end of the bundle with respect to the display screen matrix.
In any lengthwise grouping of fibers each light-receiving end of an optical fiber and a corresponding light emitting face thereof will result in point correspondence between the faces to form a minor image relationship when viewed from the display end.
If one imagines a stack of 20 logs arranged to form 4 layered rows of 5 logs each and one faces one end of the stack and counts three rows down second log in, its corresponding end at the other face is third row down, 4th log in. This is the way coherent bundles of optical fibers are arranged. Differing arrangements are known as non-coherent or reorganized fiber arrangements and constitute the basis of the fiber organization for this invention.
While coherent bundles are still used in optical fiber display devices, the devices are generally costly to fabricate by known techniques due to the necessity of connecting each end of an image receiving fiber to the corresponding end of an image-projecting fiber in the same spacial relationship which heretofore has been accomplished manually.
Moreover, no unusual display "special effects" are accomplished in this manner, such as dramatic variations in color, fade-in and fade-out, wipe-in and wipe-out, exploded images and imploded images, variations in brilliance, and the like, all of which can be accomplished by using non-coherent or reorganized fibers in accordance with the present invention.
Accordingly, it is a principal object accomplished by the present invention to provide a relatively low cost optical fiber display device and method for producing images for same which overcomes the aforesaid difficiences of the prior art, and at the same time facilitates intermittent defined image projection and "special effects" in the same device.